physics investigatory on Electromagnetic induction
1. 1. If a magnet is moved into a coil of wire
a current is induced in the wire.
2. If the magnet is moved out of the coil
the direction of the current is reversed
3. A wire, or coil of wire, cutting through
a magnetic field will generate a
voltage. This induced voltage causes a
current to flow through the wire
Electromagnetic InductionElectromagnetic InductionElectromagnetic InductionElectromagnetic Induction
7. The size of the induced voltage can be
increased if;
• the wire is moved faster
• the magnet is stronger
• the number of turns on the coil is
increased
• the area of the coil is greater
Increasing the voltageIncreasing the voltageIncreasing the voltageIncreasing the voltage
10. 1. Electricity is generated by rotating a
coil of wire in a magnetic field or by
rotating a magnet inside a coil of wire.
This is how a generator works
Generators and DynamosGenerators and DynamosGenerators and DynamosGenerators and Dynamos
14. 1. Transformers can be used to change
the voltage of an a.c. supply.
2. A changing magnetic field in the
primary coil induces a voltage in the
secondary coil
3. Transformers only work with
alternating voltage
TransformersTransformersTransformersTransformers
16. 1. Step-up transformers produce high
voltages so that little energy is lost in
power lines (National Grid)
2. Step-down transformers reduce
voltages before the electricity reaches
our homes
3. Primary voltage/Secondary voltage =
Number of turns on primary/Number of
turns on secondary
Step-up & Step-down TransformersStep-up & Step-down TransformersStep-up & Step-down TransformersStep-up & Step-down Transformers